Loud speaker



Dec. 25, 1928. 6 1,696,863

A; F. RANDALL ou!) SPEAKER F'iled Sept. v, 1926' Patented a. ,25,"192s,.

My invention relates to sound apparatus and UNITED. sTA"T -as,rATE'NT.OFFICE.

' ART UR F. RANDALL, or BOSTON, MASSACHUSETTS.

- 1.01m srEAxER.

Application filed September 7 1926. serial in. 133,953.

particularly to "electrically operated loud speaker's suclras are'usedfor radio reception. 1

The main object-of my inventionis'to provide an electrically operatedloud speaker of simple and efiicient construction which will Operatewith clarity volume'and accnracy'of reproduction.

' Figure 1 is a central .To. these-endsI have provided 'a loud speakerhaving the peculiarffeatures of con struction and mode oi operation setforthin 1 the following, description, the several novel features of theinvention being particularly pointed out and defined in the claims .atthe close thereof. a k

In the accompanying drawings:

vertical sectional View of a loud .speaker constructed in accordanceshown in Fig. 1.

I gree taper,

. instrument shown in with my invention.

Figure 2 is a front view of the'instrument Figure 3 is a rear view of aportion of the Fig. 1. a

.My new loud speaker, as herein shown, comprises a conical horn 1 which,as indicated'in Fig. 11, is preferably made with a sixty :de-

horn is secured a phone unit 2, said unit being wholly supported by thehorn 1.

At or near its larger end the horn'l is provided with an outwardlyextending diaphragm flange3 whichis preferably of the conical shapeshown, and whose annular wall is preferably at rightangles to the wallof the horn-1 asindicated in Fig. '1 of the drawingsv That flange 3 'isapproximately at right angles to the wall of the horn 1 and the two aredis posed oppositely with relation to each other so that horn -1occupies a position almostwhol- 1y within the conical flange 3.1"Thean'gular relationship referred to, however, may be varied and I havesecured excellent results with the walls disposed at other engles thanthat described, but the best results in volume and elearness weresecured with-the particular relationship described. The conical flange 3is made with' a marginal portion 4 that is flat and occupies-a positionbetween two rings 5 and Gmade from mill-board, wood or othersuitable'material,

said rings being clamped together against opposite sides of said flatmarginal portion by means of bolts7.

producing "the flange.

and to the smaller end f-this is, with the form of construction hereinillustrated, ,the conical diaphragm The horn 1 is made Witlia metalterminal 1 into the smaller. end of which is trictionally fitted, orsoldered, the nipple 8 of the metal" housing 9 of thephone unit 10 ofthe latter being thus disposed opposite, and close to,'the rear smallerend of the horn 1. v When the speaker is operating the dia-' p m 10 P ihorn l-which inturn vibrates the conical flange?) so that the latter isthereby caused to PIOJGCt sound waves also. Theresult is a of thehousing 9 are trans- Two of the bolts 7. are utilized to' fasten 8 .of ahinge 11 to the rear one of the leaves side of the ring 6, and'the otherleaf of this h nge is fastened to the upper end of a leg consIstingof-two sections 12 and .13 hinged together at 14. At its lower end' theleg 12-13 85 is provided with a laterally extending foot 15, to hold-theinstrument against rolling sidewise. This leg serves as a' prop tosupport the instrument a substantially upright position. The born 1 withits flange3 is preferably madefrom paperor the like.

What I claim is: A 1. A sound of sheet material rigidly connected'adjacent its middle with the small reversely disposed conical memberof. sheet material,

supported by said relatively small member, said operating meansincluding adirect acting armature diaphragm closing the smaller endof-therelatively small member and an electromagnet rigidly fixed to saidrelatively 105 small member. 7 I

2. A sound producing instrument comprising two .oppositely disposedhollow conical frustum members of different sizes whereof the larger endof the small member is con- 110 nected with the smaller end of the largemember; a direct acting sound producing 2, the diaphragm 0 cts soundwaves through the '65 pitch apparently controlled by ,both thevibrations of the andflange 3th'us giving producing instrument comprising a relatively large hollow conical member larger end of a relatively,I

and electromagnetic operating means rigidly connected.with'anowholly forvibrating said diaphrag armature diaphragm connected with and closingthe smaller end of the small member, and an electro-magnet rigidlyconnected with and wholly supported by the small member m and said largemember at sound frequencies. 3. A sound producing instrument comprisinga horn of sheet material; a direct actconnected with and closing thesmaller end of said horn; a direct acting conical sound producingdiaphragm flange of sheet material rigidly connected adjacent its middlewith the larger end of said horn and reversely disposed so as to inclosethe latter approximately throughout its length, and electricallyoperated means connected with and wholly supported by said hornfor'vibrating" said closure diaphragm and said flange at soundfrequencies.

mg sound producing armature diaphragm 4. A sound producing instrumentcompris ing a hollow member of sheet material serving v direct actingsound producmg armature dia-- phragm connected with and closing theopposite end of said hollow member electrically operated means connectedwith and wholly supported by said hollow member for vibrating saidclosure diaphragm and said conical flange at sound frequencies, andmeans engaging only the. marginal portion of said conical flangefor-supporting said flange, said hollow member, said closure diaphragmand said electrioally'operated means.

ARTHUR F. RANDALL.

